Abstract: A new method for the estimation of maximum instantaneous distortion contour maps is proposed based on the Fletcher Reeves nonlinear optimum theory in this paper.In the method,the maximum instantaneous distortion values are obtained by experiments or predicted by statistical methods;The Fletcher Reeves nonlinear optimum method is used to determine the pressure distribution that makes the distortion value be equal to the given maximum instantaneous value.A comparison between the estimated and experimental maximum instantaneous distortion contour maps shows that the method described in this paper can accurately predict the range and position of high and low pressure regions,and the position and shape of large gradient of pressure region.